Thanks for the insight. I totally take your word for it about balance of gameplay, not having played it yet.
Interesting, I went back into the map just now and saw something I had missed before. The banner page says "Version 1.9.3, It's December 8,1941", not the 7th, so perhaps the whole premise is that indeed the carriers and some battleships survived, which is reality, and the Japanese retained the option of going back in for another strike to finish what they started.